Data integration refers to the creation of an integrated view over various types of data typically collected from different sources. Augmented reality (AR) is one of these data integration technologies that enhances or augments a user's perception of the real world with virtual information generated from a data processing system (e.g. computer). In a typical AR system, a user's view of a real-world scene is overlaid or integrated with a computer-generated virtual image(s). It holds great promise in various fields of application, such as advertising, navigation, military services and entertainment to name a few.